Source Area Research Articles

Comprehensive drought risk assessment of the Yangtze River Basin considering socio-natural systems — Based on PCR-GLOBWB model

Against the backdrop of climate change and the impact of human activities, the regional and global risks of drought disasters are increasing. It is imperative to undertake thorough assessments of drought risks and delve into the underlying factors influencing them. This is essential for devising effective disaster risk management strategies and fostering sustainable development within the region. However, the spatial macroscopic nature of statistical data and the incomplete evaluation framework pose great challenges to finely quantify regional drought risks. In addressing these issues, with robust data support from the PCR-GLOBWB model and introducing more comprehensive evaluation indicators, we have developed a comprehensive drought risk assessment system covering the subsystems of drought hazard, vulnerability, and exposure. A comprehensive evaluation of drought risk in the Yangtze River Basin was conducted, and identifying the primary influencing factors. The results indicate that, (1) Areas with moderate or high drought hazard account for 58% of the Yangtze River Basin, while drought vulnerability exhibits a noticeable increasing trend towards the west, and regions with high drought exposure primarily concentrated in the midstream and downstream; (2) Areas with moderate or high drought risk are mainly distributed in the source area and central regions of the upstream of the basin, as well as in the densely populated and widely distributed farmland areas of the midstream and downstream. From upstream to downstream, the proportion of areas at high drought risk is 31.2%, 15% and 19.1%, respectively. (3) The hazard and vulnerability of drought are the main factors leading to high drought risk in the upstream, while higher drought vulnerability and exposure together contribute to drought risk in the midstream and downstream. Different sub-basins should develop tailored measures based on the specific factors contributing to drought risks to effectively mitigate and withstand these challenges.

Bibliometric Analysis of IJISS Journal based on Citation and Publication Relevant Metrics

This research is a bibliometric assessment of the Google Scholar-indexed Indian journal of Information Sources and Services. The articles published in the journal between 2019 and 2024 are evaluated bibliometrically in this study. A data set was created using Microsoft Excel from information retrieved from the journal's website. By looking at things like document types, authors, Degree of collaboration, collaboration coefficient and collaboration indexes, and citation indicators, bibliometric assessments can get a sense of the composition and distribution of published works. In addition to the number of cited publications, the study has investigated other aspects of these journals, such as the h-index and i-index. People looking for high-quality journals in the area of information sources and services will find this paper to be an important piece of information. Those who have perused the most prominent journals included in Google Scholar's database yet found the information they offered to be insufficient will find this article especially informative.

Study of seasonal variation of accident-derived atmospheric radiocesium in Koriyama City, Fukushima Prefecture, Japan during 2011-2014.

This study measured the atmospheric concentration and deposition flux of radiocesium in Koriyama City, Fukushima Prefecture, Japan, from November 2011 to October 2014. The results show synchronous seasonal change in atmospheric concentration and deposition flux of radiocesium, which is high during winter to early spring and low during summer to autumn. These seasonal variations are similar to those observed in Fukushima City but differ from those in Namie Town, Fukushima Prefecture, comprising a larger contaminated forest area. The evaluation of the relationship between atmospheric 137Cs concentration or 137Cs specific activity in atmospheric particulate matter (PM) and deposition density of 137Cs in PM source area suggest that stronger winds blowing from areas with relatively large 137Cs deposition (west of Koriyama City) toward the study site affect the site's atmospheric 137Cs concentrations.

An Appraisal Of The Impact Of Leachates From A Waste Dumpsite On Coastal Soils And Groundwater System Of The Metropolitan Area Of Lagos, Southwestern Nigeria

Open dump being the common waste disposal practice in most of the urban centres has posed serious challenges to groundwater quality especially within its vicinity. This study assessed the impact of solid waste disposal on the quality of groundwater and soils in Oke-Odo area of Metropolitan Lagos, Nigeria. Field physicochemical parameters such as pH, electrical conductivity (EC), total dissolved solids (TDS) and temperature were measured using PC Testre Model 35. A total of 36 water samples, two leachate samples and 15 soil samples were analyzed for their major ions and trace metal components using titration and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) methods. Results revealed a decrease in concentrations of trace and major elements with respect to their distance from the waste dumpsite. A decrease in concentrations of Fe was observed with distances from the dumpsite with values ranging from 12.6 to 0.03mg/l and 4.3 to 0.03mg/l for samples within 500 m and 500-1,500 m, respectively. With exception of a few locations having higher concentrations of Fe, Al, Br, Cu, Mn and Pb, the groundwater sources in the study area are chemically potable with respect to their chemical compositions and generally conform to the World Health Organization and the Nigerian Standard for drinking Water Quality standards for drinking water; and thus, fit for domestic purposes. Sodium adsorption ratio ranges between 0.82 and 5.80 %, indicating low sodium and medium to high salinity hazards. This implies suitability of the water for irrigation purpose. The leachate from the active part of the waste dumpsite showed high concentrations of heavy metals such as Pb (4 mg/l), Cd (0.7 mg/l), Zn (6.54 mg/l) and Cu (3.57 mg/l), which indicates a potential environmental risk. The absence of these metals in the groundwater can be attributed to the attenuating role of the soil above the water table as confirmed by higher concentration of the measured trace metals in comparison to the control sites, with values ranging from 280 to 636 mg/l for Pb, 2 to 9.9 mg/l for Cd, 1041 to 10,000 mg/l for Zn and 102 to 1,307 mg/l for Cu. A total of 66.6 % of soil samples havevery high degree of contamination while 33.3% is considerably contaminated. Hydrochemical characterization of the water revealed predominant Na-K-Cl end-member water type and Ca-Mg-Cl water type which could be attributed to the influence of leachate from the waste dumpsite and possible contribution of seawater from the adjoining lagoons and cation exchange process. This study has revealed that soils and groundwater quality within the vicinity of Oke-Odo dumpsite has been impacted minimally.

Impact of source (drain) doping profiles and channel doping level on self-heating effect in FinFET

In this work the impact of the doping profile in the source and drain areas on the self-heating effect in SOI FinFET is simulated at different doping levels in the channel. Constant profile as well as two types of analytical profiles are considered. The impact of the doping profile on the threshold voltage and on the ratio Ion/Ioff at different doping levels of the channel is also considered. To consider the self-heating effect the thermodynamic transport model in TCAD Sentaurus software is used for simulation. The results of simulation show that self-heating effect, threshold voltage, and Ion/Ioff ratio considerably depend on the doping profile in source and drain areas.

Flowslide on a fill slope triggered by a burst water pipe: a case history

This paper presents a case study in Hong Kong of a flowslide occurred on a fill slope triggered by a burst water pipe buried near the slope crest. The onset of failure was recorded by nearby pedestrians and the video was immediately posted in social media which had caught noticeable public attention. The flowslide resulted in a temporary closure of an undermined road section at the slope crest. The debris travelled over 500 m down the natural hillside within a country park. No casualties were reported. History of the site was studied. Information was collected to establish the chronological order of events happened before the flowslide. Post-landslide investigations including field mapping in the source area and along the debris trail, ground investigations, and a fluid-coupled numerical study were undertaken to examine the probable cause and mechanism of the failure. It is diagnosed that the high mobility of this landslide would be caused by the saturation of a loose fill layer in the slope due to water egress from the burst pipe which in turn might have triggered a static liquefaction of the loose fill. Lessons learnt from this case history and measures to minimize similar landslide hazard on other fill slopes with similar settings are discussed.

Ecosystem Service Value Estimation and Ecological Security Pattern in Heilongjiang Province

To maintain ecosystem functions and ensure ecological security, estimating the value of ecosystem services and constructing an ecological security pattern are necessary. Considering the lack of systematic research on the estimation of ecosystem service value and the construction of ecological security pattern, this study extracted the ecological source based on the analysis of ecosystem service value and morphological spatial pattern. According to the natural conditions such as geographical location and altitude, land use type, landscape pattern type, elevation, slope, and normalized difference vegetation index were selected to establish the resistance surface. The minimum cumulative resistance model was used to identify potential ecological corridors, so as to construct the ecological security pattern of Heilongjiang Province, and longitudinal analysis was conducted from 2000 to 2020. The results showed that： ① The overall value of ecosystem services in Heilongjiang Province showed an upward trend （with an amplitude of 42%）, the value of hydrological regulation services accounted for the largest proportion among different service types （approximately 30%）, and the value of forest land services accounted for the largest proportion among different land use types （up to 70%）. ② Eight ecological source areas were extracted, mainly distributed around Greater Khingan Mountains, Lesser Khingan Mountains, Changbai Mountain, and Wanda Mountain, with the largest area of ecological source in Greater Khingan Mountains. ③ Twenty-eight potential ecological corridors were identified, mainly distributed in the northeastern side of the line from Heihe City to Mudanjiang City, forming densely populated areas in Qitaihe City, northern Mudanjiang City, and southern Jixi City. ④ An ecological security network pattern in Heilongjiang Province was constructed with Greater Khingan Mountains Region, Mudanjiang City, and Shuangyashan City as endpoints and Yichun City as the center, finding that the main problem faced at that time was uneven spatial distribution. The research results are helpful to formulate and establish more reasonable ecological environment protection measures and policies and can provide reference value and scientific basis for provincial ecosystem protection and optimization.

Characteristics, Transport Routes, and Potential Sources of PM2.5 and O3 Pollution in Suzhou

Based on the air quality and meteorological data in Suzhou from 2015 to 2022, the long-term variations in PM2.5 and O3, meteorological characteristics, and their correlations were analyzed in this study. The HYSPLIT model was used to explore the main transport pathways and potential source areas of PM2.5 and O3. The results showed that： ① The annual averaged concentrations of PM2.5 in Suzhou decreased steadily during the study period, and the annual average concentration from 2020 to 2022 reached the national second-level standard limit. However, the annual average concentrations of O3 all exceeded the national second-level standard limit. After 2017, the annual number of days that O3 exceeded the standard was always higher than that for PM2.5. The number of days of compound pollution continuously decreased from nine days in 2015 to zero days in 2020, and there was no compound pollution since then. ② The most severe pollution seasons for PM2.5 and O3 were winter and summer, respectively. PM2.5 pollution was more likely to occur in low-temperature and high-humidity weather, while O3 pollution was more frequent in high-temperature and low-humidity weather. Wind direction played an important role, with northwest winds amplifying PM2.5 pollution and southeast winds boosting O3. These two pollutants showed a strong correlation in summer with a coefficient reaching 0.73. ③ Cluster analysis revealed that trajectory two from Hebei Province in spring and trajectory four from Shaanxi Province in winter were prone to an increase in PM2.5 concentration. The short to medium distance trajectory 1 from Shandong Province in summer and trajectory two from Hebei Province in spring were prone to an increase in O3 concentration. ④ The analysis of potential source areas showed that transportation outside the province had a significant impact on PM2.5 and O3 pollution in Suzhou. The potential source areas of PM2.5 in spring and winter were mainly distributed in Anhui Province, Henan Province, and Hubei Province； the potential source areas in autumn were mainly distributed in Hubei Province and Jiangxi Province； and the potential source areas of O3 in spring and summer were mainly located in the Beijing-Tianjin-Hebei Region, Shandong Province, Henan Province, and Shanxi Province. Valuable management insights for the coordinated control of PM2.5 and O3 pollution in Suzhou were put forward based on this study.

Floods of Egypt’s Nile in the 21st century

Extreme precipitation and flooding events are rising globally, necessitating a thorough understanding and sustainable management of water resources. One such setting is the Nile River’s source areas, where high precipitation has led to the filling of Lake Nasser (LN) twice (1998–2003; 2019–2022) in the last two decades and the diversion of overflow to depressions west of the Nile, where it is lost mainly to evaporation. Using temporal satellite-based data, climate models, and continuous rainfall-runoff models, we identified the primary contributor to increased runoff that reached LN in the past two decades and assessed the impact of climate change on the LN’s runoff throughout the twenty-first century. Findings include: (1) the Blue Nile subbasin (BNS) is the primary contributor to increased downstream runoff, (2) the BNS runoff was simulated in the twenty-first century using a calibrated (1965–1992) rainfall-runoff model with global circulation models (GCMs), CCSM4, HadGEM3, and GFDL-CM4.0, projections as model inputs, (3) the extreme value analysis for projected runoff driven by GCMs’ output indicates extreme floods are more severe in the twenty-first century, (4) one adaptation for the projected twenty-first century increase in precipitation (25–39%) and flood (2%-20%) extremes is to recharge Egypt’s fossil aquifers during high flood years.

Utilizing black yeast for sustainable solutions: Pioneering clean energy production and wastewater treatment with Exophiala dermatitidis

A single-chamber microbial fuel cell (MFC) was constructed to assess the capacity of Exophiala dermatitidis EXF-8193 as an electron-donating microorganism. Unidirectional carbon fiber electrodes were used, and voltage generation was monitored over 120 hours. The system achieved a maximum voltage of 176 mV after 93 hours of operation. Simultaneously, the decolorization of Basic Blue 9 (BB9) dye was evaluated, achieving 70% degradation within 120 hours. Initial optimization studies focused on individual variables, including carbon source, anode shape, and anodic surface area. Results indicated that glucose, a T-shaped anode, and an anodic area of 12 cm² were optimal, yielding voltage values of 175.8 ± 0.57 mV, 175.8 ± 0.57 mV, and 310.53 ± 1.22 mV, respectively. In the second stage, a multiparametric optimization was conducted using Response Surface Methodology (RSM) with a Box-Behnken design, resulting in a second-order model with an R2 of 91.7. Under optimized conditions, the MFC reached a favorable maximum voltage of 284 mV, demonstrating enhanced performance with fine-tuned operational parameters. These findings represent a pioneering step in exploring black yeast, particularly E. dermatitidis, as a sustainable bio-catalyst in MFC technology. This study opens new avenues for further research on extremophilic fungi in bioenergy production and wastewater treatment, highlighting the need for continued exploration of black yeast's unique properties in biotechnological applications.

The alien and invasive plant species that may be a future conservation threat to the Lesotho Afro-alpine Drakensberg area

In this study, we documented and compared similarities of the alien plant species richness between South Africa represented by three provinces: Free State (FS), Eastern Cape (EC), and KwaZulu-Natal (KZN), and Lesotho—an important water source area for southern Africa. We tested the prediction that alien plant species in Lesotho are a subset of South Africa’s species partly because of the short geographical distances between the provinces and Lesotho, and environmental similarity. Overall, 7124 records containing 1040 individual alien plant species belonging to 147 families were documented. South Africa had significantly greater alien plant species records than Lesotho. Of 147 plant families, 44 were represented in both countries, and 101 families did not occur in Lesotho. Against the study prediction, the Geraniaceae and Orobanchaceae families occurred in Lesotho but not in three provinces. KwaZulu-Natal had a significantly greater number of species than Lesotho but not the other provinces, and 49% of species in three provinces originated from the Americas (i.e. South and North), Europe, and Asia. A similar pattern was observed in Lesotho. Woody and herbaceous alien plants, habitat transformers, dominated three provinces, while herbaceous species dominated Lesotho. The 62% of 1040 alien species were not listed in the South African national regulations, indicating their negative impacts are also unknown in the study region. Plant nurseries were a dominant species dispersal pathway in South Africa, while home gardens were prominent in Lesotho. We conclude that invasive plant species constitute a future threat to the Lesotho Drakensberg highlands water catchments and recommend prioritising their management and improving cross-border biosecurity between Lesotho and South Africa.

Probabilistic seismic demand analysis for bridges based on earthquake scenarios

The current probabilistic seismic demand analysis of structures predominantly considers the correlation between the ground motion intensity measure (IM) and structural seismic demand, but fails to effectively capture regional source characteristics. It is essential to integrate earthquake engineering with seismic response of structures using source parameters to quantify regional ground motion uncertainties and determine appropriate IMs. This study presented a probabilistic seismic demand analysis method for structures based on earthquake scenarios, characterized by 1) utilizing the stochastic finite-fault method to simulate ground motions at a specific site instead of employing multiple seismic waves from different source areas, and 2) incorporating the correlation between IMs and the key indicator of source parameters, stress drop, into the probabilistic seismic demand analysis. Taking a continuous girder bridge as an example, the performance of the stress drop and 14 individual IMs in predicting the longitudinal seismic demand and reflecting source characteristics was evaluated. The results revealed that it was difficult to establish a reliable relationship between the stress drop and structural seismic demand. Owing to the complexities of ground motion and structural parameters, the individual IMs were challenging to effectively capture their characteristics simultaneously. Therefore, composite IMs have been proposed to cover the characteristics of both the source and seismic demand. The optimal solutions were derived using a multi-objective genetic algorithm, which exhibited desirable capabilities in both aspects, providing a comprehensive guide for the seismic performance assessment of regional transportation networks.

Incorporating meander to account for the impact of low winds in area source modeling; AERMOD as a case study

ABSTRACT A variety of sources of pollutant emissions can be represented as area sources. These include manure lagoons, landfills, wastewater treatment ponds, and highways. A group of point sources can also be treated as an area source. The impact of an area source is usually computed by representing the area source as a set of line sources perpendicular to the wind direction. As for point sources, the Gaussian horizontal concentration distribution used to compute the contributions of the line sources is likely to overestimate ground-level concentrations when the wind speed is comparable to the standard deviation of the horizontal velocity fluctuations. A variety of methods are used to mitigate this overestimation under these conditions, referred to as meander. As an example of one these approaches, we examine that of AERMOD, EPA’s regulatory model. AERMOD includes meander in modeling the impact of point and volume sources, but has not yet incorporated it into AERMOD’s area source algorithm. This paper describes an approach to include meander in AERMOD’s area source algorithm and demonstrates its impact on concentrations associated with area sources. Implications: Inclusion of wind direction meander in modeling dispersion when the wind speed is low is important in ensuring that AERMOD does not overestimate concentrations under these conditions. In view of the importance of area sources of pollution, the results presented in this paper represent a potential enhancement of AERMOD’s ability to estimate the upper end of the concentration distribution, which forms the basis of the regulatory acceptance of the model.

Characterization of atmospheric arsenic wet deposition transport pathways and potential sources areas in the Pearl River Delta region

This study tracked the characteristics of atmospheric wet deposition of the toxic element arsenic (As) at both urban (Guangzhou (GZ)) and forested (Dinghushan Natural Reserve (DHS)) sites within the Pearl River Delta (PRD) region between 2016 and 2019, examining its correlation with rainfall patterns. Additionally, by employing backward trajectory analysis and the potential source contribution function (PSCF) in conjunction with pertinent emission inventories, we pinpointed the main pathways of atmospheric arsenic transport and evaluated the emission contributions from priority source areas. The study revealed that the atmospheric arsenic wet deposition fluxes at the GZ and DHS sites exhibited a trend of increase followed by a decrease over the four-year period. Wet season deposition fluxes were more than triple those of the dry season, with urban site showing a difference of over four times. Notably, wet season As deposition at both sites was predominantly affected by heavy rainfall from marine air masses, constituting 31% of the total deposition. The predominant trajectory directions contributing to arsenic deposition at GZ and DHS were northeast (55%) and south (53%), respectively. The primary source areas for both sites were largely outside the PRD region, with the GZ site having 80% to 95% of its source area in the non-PRD region, compared to 69% to 88% at the DHS site. Furthermore, non-PRD areas contributed approximately 65% to arsenic emissions for both sites, with the industrial sector being the dominant emission source, exceeding 97% of the total emissions.

Antimony Flux and Transport Dynamics in a Mining‐Impacted River Is Linked to Catchment Hydrodynamics and Climate Oscillations

ABSTRACTWe investigate how seasonal flow variations and a climatic regime that is dominated by the El Niño–Southern Oscillation (ENSO) influence Sb flux dynamics in an Australian river impacted by mining. Sampling (n = 496) spans a hydrologically complex 7‐year period of drought, bushfires and floods from 2016 to 2023, during which 17% of samples exceeded the Sb drinking water guideline concentration (3 μg L−1). Aqueous Sb (SbAq) concentration–discharge (C–Q) relationships are non‐continuous/non‐linear across the flow range, with chemodynamic behaviour at moderate flows reflecting hydrological connection to the primary Sb‐source area combined with variable dilution. In contrast chemostatic behaviour occurred at extreme low and high flows, reflecting hydrological disconnection from the source area and persistent dilution, respectively. SbAq was significantly positively correlated (p < 0.01, Spearman's ρ = 0.58) with a Q index representing the proportional contribution of sub‐catchment flow from the mineral‐field area, suggesting sufficient localised rainfall in the Sb mining‐impacted sub‐catchment contributes to downstream peaks in SbAq concentrations. Aqueous and particulate Sb (SbP) annual loads (La) during the study period spanned 24–5174 and 1.2–2820 kg, respectively and were strongly flow dependant with extreme interannual variability reflecting dry and wet years. We extrapolate daily load‐daily discharge (Ld–Qd) relationships for SbAq and SbP to estimate Ld over a 53‐year period (1970–2023) of continuous Q data (mean total Sb La = 1865 kg ± [SE] 247). Positive correlations between the annual Southern Oscillation Index and both Sb La (p < 0.05) and proportional SbP La over 53 years suggests ENSO fluctuations influence annual Sb transport dynamics. Upstream SbP load estimates correspond with downstream estimates of coastal floodplain sedimentary Sb mass, with approximately 10%–45% of the estimated SbP exported downstream since approximately 1880 accumulated on the Macleay coastal floodplain. Data suggest at current rates of export, complete flushing‐leaching of mine tailings‐derived Sb from the upper Macleay catchment may take in the order approximately 600–1000 years.

The Upper Devonian to Lower Carboniferous Billefjorden Group on Bjørnøya, Svalbard, and Its North‐Eastern Greenlandic Provenance

ABSTRACTIn this contribution, we document changes in detrital zircon ages in the upper Devonian (Famennian) to lower Carboniferous (Mississippian) Billefjorden Group on Bjørnøya, the southernmost island of Svalbard. This alluvial, coal‐bearing clastic succession is widely distributed across the archipelago and the Barents Shelf. The sediments were deposited in subsidence‐induced lowlands that formed just after regional post‐Caledonian collapse‐related extension, which created the classical ‘Old Red Sandstone’ basins during the Devonian, and prior to localised rift‐basin development in the middle Carboniferous (Serpukhovian–Moscovian). Moreover, the succession is little affected by Ellesmerian compressional deformation, which occurred in the latest Devonian. However, little is known of the provenance and regional sediment routing in this tectonically transitional period between the post‐Caledonian structuring events in the Devonian and the middle Carboniferous rifting. It has previously been invoked that a regional fault running parallel to the western Barents Shelf margin, the West Bjørnøya Fault, controlled sedimentation in the area. Here, we combine detrital zircon U–Pb ages and sedimentological data to investigate stratigraphic provenance variations and test whether tectonics controlled deposition of the Billefjorden Group on Bjørnøya. Sedimentological investigations demonstrate changes in fluvial style with intercalations between successions dominated by meandering channel fills and abundant overbank fines to sandstone‐dominated sheet‐like successions of braided stream origin. Palaeocurrent data show that two competing drainage directions accompany the changes in fluvial architecture. Northeasterly transport directions, recorded in the braided stream deposits, indicate possible fault‐transverse drainage. The detrital zircon content in these deposits indicates sourcing from Caledonian terranes in Northeast Greenland. Northwest‐oriented transport directions, measured in the meandering channel deposits, are inferred to represent axially positioned drainage systems. These may have been sourced from either Northeast Greenland, a more localised source, or Baltica. The latter would require long‐distance sourcing, which, given the tectonic setting of the region, seems unlikely. Although our sedimentological observations point to syn‐tectonic deposition, this is not clearly captured in the detrital zircon data, suggesting a common source for the Late Devonian–Mississippian fluvial systems of Bjørnøya. Thus, combined with previously published provenance data from Svalbard and Greenland, we demonstrate that the East Greenland Caledonides formed a long‐lived and significant source area which provided sediments to nearby basins from the Devonian to the Early Cretaceous.

Source apportionment of PM2.5 using dispersion normalized positive matrix factorization (DN-PMF) in Beijing and Baoding, China

Fine particulate matter (PM2.5) samples were collected in two neighboring cities, Beijing and Baoding, China. High-concentration events of PM2.5 in which the average mass concentration exceeded 75 µg/m3 were frequently observed during the heating season. Dispersion Normalized Positive Matrix Factorization was applied for the source apportionment of PM2.5 as minimize the dilution effects of meteorology and better reflect the source strengths in these two cities. Secondary nitrate had the highest contribution for Beijing (37.3 %), and residential heating/biomass burning was the largest for Baoding (27.1 %). Secondary nitrate, mobile, biomass burning, district heating, oil combustion, aged sea salt sources showed significant differences between the heating and non-heating seasons in Beijing for same period (2019.01.10–2019.08.22) (Mann-Whitney Rank Sum Test P < 0.05). In case of Baoding, soil, residential heating/biomass burning, incinerator, coal combustion, oil combustion sources showed significant differences. The results of Pearson correlation analysis for the common sources between the two cities showed that long-range transported sources and some sources with seasonal patterns such as oil combustion and soil had high correlation coefficients. Conditional Bivariate Probability Function (CBPF) was used to identify the inflow directions for the sources, and joint-PSCF (Potential Source Contribution Function) was performed to determine the common potential source areas for sources affecting both cities. These models facilitated a more precise verification of city-specific influences on PM2.5 sources. The results of this study will aid in prioritizing air pollution mitigation strategies during the heating season and strengthening air quality management to reduce the impact of downwind neighboring cities.

Monte Carlo Simulation As Precision Predictive Tools to Find Isodose Curve of Gamma Irradiator: A Preliminary Study

&lt;span lang="EN-AU"&gt;Dose distribution mapping is critical for guaranteeing correct sample irradiation, with both experimental and simulation methods playing important roles. Simulations are an effective way to forecast dose distribution patterns, lowering costs and increasing resource utilization. The geometry, source configuration, and measurement locations are fundamental to determine. The gamma irradiator has 48 source areas, each containing two cobalt-60 pencils measuring 8.15 cm, as well as a 4.7 cm stainless steel dummy. Alanine dosimeters were used for dose assessments, and stability varied by less than 1% over six months at 6°C and up to 5% at 50°C. The study's findings revealed a 2.25% disparity in relative dosage between experimental measurements and PHITS models. This result is a major improvement over prior research that found a 10% difference. Furthermore, dosage mapping along the XY and Z axes revealed the most uniform zone on the Z-axis, measuring 7.5 cm to 12.5 cm and with a radius of no more than 5 cm. These findings contribute to our understanding of dose distribution in gamma irradiation and highlight the utility of Monte Carlo simulations for optimizing irradiation operations. The study implies that this model can be used to improve the arrangement of cobalt-60 pencils in the irradiator, improving homogeneity and radiation outcomes.&lt;/span&gt;

Acceleration of the Hydrological Cycle under Global Warming for the Poyang Lake Basin in Southeast China: An Age-Weighted Regional Water Tagging Approach

Abstract Global warming is assumed to accelerate the global water cycle. However, quantification of the acceleration and regional analyses remain open. Accordingly, in this study, we address the fundamental hydrological question: Is the water cycle regionally accelerating/decelerating under global warming? For our investigation, we have implemented the age-weighted regional water tagging approach into the Weather Research and Forecasting (WRF) Model, namely, WRF-age, to follow the atmospheric water pathways and to derive atmospheric water residence times defined as the age of tagged water since its source. We apply a three-dimensional online budget analysis of the total, tagged, and aged atmospheric water into WRF-age to provide a prognostic equation of the atmospheric water residence times and to derive atmospheric water transit times defined as the age of tagged water since its source originating from a particular physical or dynamical process. The newly developed, physics-based WRF-age model is used to regionally downscale the reanalysis of ERA-Interim and the Max Planck Institute Earth System Model (MPI-ESM) representative concentration pathway 8.5 scenario exemplarily for an East Asian monsoon region, i.e., the Poyang Lake basin (the tagged water source area), for historical (1980–89) and future (2040–49) times. In the warmer (+1.9°C for temperature and +2% for evaporation) and drier (−21% for precipitation) future, the residence time for the tagged water vapor will regionally decrease by 1.8 h (from 14.3 h) due to enhanced local evaporation contributions, but the transit time for the tagged precipitation will increase by 1.8 h (from 12.9 h) partly due to slower fallout of precipitating moisture components. Significance Statement Global warming is assumed to accelerate the global water cycle. However, quantification of the acceleration and regional analyses remain open. This study presents the newly developed WRF-age model that allows us to follow the atmospheric water pathways, to derive atmospheric water residence times and atmospheric water transit times. We exemplarily show for an East Asian monsoon region that global warming leads to regionally decreased residence time for the tagged water vapor in the atmosphere due to enhanced local contributions, but increased transit time for the tagged precipitation over the land surface that is partly attributed to slower fallout of precipitating moisture components in the atmosphere. These findings reveal the physical mechanisms behind dry-getting-drier at regional scales.

Flood regulation ecosystem services analysis and security pattern optimization for resilient management adapted to the complex terrain of coastal estuaries: A case study in Xiamen

The flood risk in coastal areas has been exacerbated by global climate change. Research on flood risk assessment is emerging from the perspective of supply and demand for flood regulation ecosystem services (FRES). However, there are still limitations in the evaluation of lowland regulation, implementation of intelligent algorithms, comparison of multi-grain FRES supply and demand, and overall optimization of security pattern. Therefore, we propose a comprehensive FRES supply assessment method that incorporates soil and vegetation, lowland, and water regulations. Additionally, we introduce the random forest model to enhance the FRES demand assessment approach. Two grain sizes of the sub-catchment area and grid unit are used to compare FRES supply and demand. Using Xiamen as a case study, this research unveils the following findings: (1) Significant disparities exist between the assessment outcomes of FRES based on multiple types of regulatory services and those solely considering soil and vegetation regulation. The areas with high FRES supply extend beyond upper mountain forests to include local lower plains exhibiting strong capabilities for lowland or water system regulation. (2) Consistent yet distinct results are observed when comparing two grain sizes. Imbalances in supply and demand occur in estuaries, bays, and densely built-up regions. Sub-catchment units exhibit wider distribution and concentration, while grid units display more dispersed patterns. (3) In terms of in-situ regulation, 26.77 km2 ecological protection area, 9.85 km2 ecological restoration area, and 119.59 km2 construction land flood control intervention area are demarcated. From a directional regulation perspective, 22 FRES corridors connecting source and sink areas along with 24 pinch points are identified. Optimizing security patterns through coordinated management of FRES supply and demand can enhance the resilience of coastal estuaries.